Three- and four-coordinate copper(I) halide complexes of 2-(diphenylphosphano)benzaldehyde: Dimerization induced by thione-S ligation

Reactions of copper(I) halides with 2-(diphenylphosphano)benzaldehyde (PCHO) in 1:2 molar ratio afforded mononuclear complexes of the type [CuX(PCHO)2], whereas treatment of these compounds with equimolar amounts of pyridine-2-thione or pyrimidine-2-thione gave rise to the formation of mixed-ligand dimers of the formula [CuX(PCHO)(thione)]2. The molecular structures of [CuCl(PCHO)2], [CuBr(PCHO)2] and [CuCl(PCHO)(pymtH)]2 have been established by single-crystal X-ray diffraction. The two homoleptic complexes feature a trigonal copper(I) centre with the phosphane acting as a monodentate ligand via the P atom. In the structure of the dimeric mixed-ligand complex each of the two metal centres exhibit a distorted tetrahedral environment with the thione-S atoms acting in a doubly bridging mode.

The coordination of 2-(diphenylphosphano)benzaldehyde (PCHO) to copper(I) halides leads to the formation of trigonal planar complexes of type [CuX(PCHO)2] with the phosphane acting as a monodentate via the P atom. These complexes react with pyridine-2-thione or pyrimidine-2 thione forming dimeric species of type [CuX(PCHO)(thione)]2 in which the two CuI centres are doubly bridged by thione-S atoms. The crystal structures of three examples of the novel complexes have been characterized by X-ray crystallography.Figure optionsDownload as PowerPoint slide